When it doesn’t hit the target you set for it due to the volatile nature of the market and the bull market already over, it is good to sell them off and get the profit already accumulated. Waiting for the bull run to come when it seems unlikely to come at that time again is just like gambling and if you gamble your money, you’ll end up losing more money and get little or no profit for all the wait over the years.
If you say that selling when you have reached your bitcoin target is the best and you don't need to gamble by keeping it, is wrong because it shows that you don't know the worth of bitcoin investment and when you sell off all your investment in the nearest future you will become broke, since you don't have the investment anymore to generate profit. An investment should be seen as something that generate produt in a long term i.e till infinity. If you sell all your bitcoin, you will not reach the fuck you level status.
Imagine that you own a company and have taken time to grow this company for let's say 8yrs and the company is giving you good returns but you haven't touched a dime from the profit. If The company at a point total worth is $1m, and your dream money to have for you to know that you have arrived is $1m, will you now sell the company out to someone else for $1m because that was your price target...you will get broke again and it will be difficult to build such company from a start and achieve same worth in a very long time because of inflation and some unforeseen challenges. The best thing is to allow the profit to compound and take profit leaving the company to still worth the $1m because it is an investment that has flourished already and it will continue to bring profit. This is sane with bitcoin investment.
It is not 100% guarantee that bitcoin price will give huge profit in some timeline but the odds of having good profit us higher and this is why, when you have reached your bitcoin target, that is when you can now be relaxed with your accumulation consistently and maintain your bitcoin portfolio by buying once in a while or quarterly DCA. Then when bitcoin price reaches a new ATH, you can sell like 10% and leave the rest to continue increasing it once in a while or whatever strategy that is cool with you just to make sure that the investment is increasing in size or you can then diversify into gold, stock, bond or real estate. What matters in one's life is steady growth no matter how well your investment is flourishing, you must still make sure that you are increasing it so that you can get to a level that you will never get broke because your investments are working for you.